Rock-drill bit



, May 10,1927.

W. J. KIRBY ROCK DRILL BIT Filed April 26. 1925 ngmvron. WJJfzrbZ. BY

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Patented May 10, 1927.

WARREN J. KIRBY, OF MIAMI, ARIZONA.

ROCK-DRILL BIT.

Application filed. April 26, 1926. Serial No. 104,686.

This invention relates to a rock drill bit that may be formed on drill bars, for drill- .ing holes in rock or other substances for blasting purposes.

An object of my invention is the construction of a bit. by means of which faster drilling can be done, than is possible with the ordinary bit in use at the present time.

Another object. of the invention is the construction of a bit whereby a hole or socket can be cut in rock, or like matter, by the bit cutting a. circular groove around the wall of the hole, leaving a core like center, which is broken off by reason of the peculiar wedge-shaped structure of the cutting end of my bit; this breaking off of the core is accomplished as the cutting of the groove is being done.

With the foregoing and other objects in view, my invention comprises certain novel,

constructions, combinations and arrangements of parts as will be hereinafter fully described, illustrated in the accompanying drawings, and more particularly pointed out in the appended claims.

In the drawings:

Figure 1 is a view in side elevation of a bit constructed in accordance with the present invention, showing the same as it ap pears in operation, cutting a hole or socket in a rock, or like matter.

Figure 2 is a view in elevation of the bit turned half way around from the position shown in Figure 1.

Figure is a sectional view taken on line 3-3, Figure 1, and looking in the direction of the arrows.

Figure 1 is a sectional view taken on line 4-l, Figure 1, and looking-in the direction of the arrows.

Referring to the drawings by numerals, 1 designates the body of the bit, which is preferably round in cross section. This body is provided with which water is allowed to pass to facilitate the drilling operation; this channel or aperture 2 extends the entire length of the device.

The end 3 of the body lis adapted to be supported upon the drilling machine, and the-usual lugs 4 are provided for assisting in fastening the bit body upon the chuck.

On the lower or cutting end of the body 1,,

I preferably enlarge the end 5, causing an inclined surface 6 (Fig. 1) to be formed on one side of the body between the polnts designated by A and B. This inclined sura central aperture 2, through face 3 terminates in a straight face or portion 7 between the points designated by A-A. The extreme lower and outer end of body 1 is bevelled in an elliptic shape'at 8, whereby a small cutting edge is formed substantially elliptical shape in cross section (Fig. 1-), so that on the lower and outer end of the body 1, I have produced an oil'- set, constituted by widening or thickening the lower end of the body, producing the inclined face 6 and straight edge or face 7. It is to be noted that face or edge 7 is parallel with the longitudinal axis of the body 1. By reason of this offset wedge-like lower or outer end of body 1., when the bit is in operation, I am able to rapidly cut a small annular groove 9 (Fig. 4) in the rock bed, or any other substance upon which the drill bit is working. This cutting action is caused by the drill bit being forced against the rock, and then slightly removed and turned and then again forced against the rock, in what might be called an intermittent action, and while this cutting of groove 9 is taking place, the peculiar shape of my bit 1 breaks off the core 10, as the drill bit continually chips away the core during its inward stroke, and then turning and with another stroke, during the rotary movement of the drill bit, as is commonly done in handling an ordinary bit.

The passing of water into the hole through the channel or aperture 2, during the operation of the drill, helps to wash out the broken particles or dust, but by reason of the peculiar and eflicient structure of the cutting end of the drill, herein shown and described, the cutting of a hole in a rock, or the like is greatly facilitated, as my peculiarly constructed drill bit cuts in a peculiar manner, to wit: forms groove 9 and chips away at the same time, core 10.

It is to be understood that my drill bit may be formed on drill bars of machines for drilling purposes, such as the water liner jack hammer piston, or any other machines made with a hammer blow or a piston stroke and a self revolving mechanism.

While I have described the preferred embodiment of my invention and illustrated the samein the accompanying drawings, certain minor changes or alterations may appear to one skilled in the artto which this invention relates during the extensive manufacture of the same, and I, therefore, reserve the right to make such changes or. alterations as shall fairly fall Within the scope of the appended claims.

WVhat- I claim is:

1. As a new article of manufacture, a drill bit comprising a body 1 provided with an enlarged outer end 5 and With a comparatively large elliptic shaped bevelled surface 8, said body 1 provided With a Water channel 2 opening upon said bevelled surface 8, and said body 1 provided opposite -to said bevelled surface 8 with an inclined face (3 terminating at its outer end in a straight edge 7 parallel With the longitudinal axis of said body 1, whereby a circular groove is cut by said drill bit.

2. As anew article of manufacture, a drill bit comprising a body circular in cross section from one end to its opposite end,

said body provided with a Water channel throughout its length said body provided with an elongated elliptical shaped bevelled inner end or face, said body provided at one side of said bevelled inner end with a straight inclined face terminating gradually at its outer end in a straight face, said straight face rounded transversely and producing a small cutting point only at the inner end. of said bit, said cutting point being substantiallyelliptical shaped in cross section, whereby a small circular groove can be rapidly cut substantially as shown and described.

in testimony whereof I hereunto afiix my signature.

\VARREN J. KIRBY. 

